Sustained selective attention underlies our ability to process some parts of the environment at the exclusion of others over a period of time. Therefore, sustained selective attention is a crucially important process enabling one to process relevant information and ignore information irrelevant to the task at hand, be it language comprehension, categorization, or problem solving. However, development of the mechanisms underlying this crucially important ability is not fully understood at present. The goal of the proposed research is to investigate mechanisms of sustained selective attention in 2- to 6-year-old children, age at which this ability has been shown to develop rapidly. One of the challenges in investigating mechanisms of this ability is developing a task that is sufficiently motivating and challenging to participants of different ages. Another challenge is developing a task that makes it possible to assess automatic and voluntary components of sustained selective attention within the same experimental paradigm. The proposed research will (1) develop an engaging task suitable for investigating voluntary and automatic components of sustained selective attention across a wide range of age groups, including children as young as two years of age, and (2) utilize this task to investigate mechanisms of sustained selective attention in 2- to 6-year-old children. PUBLIC HEALTH RELEVANCE: The proposed project will initiate a new line of research investigating mechanisms of sustained selective attention in 2- to 6-year-old children using a novel computer-based Object Tracking task. In addition to generating new empirical and theoretical knowledge, the proposed research will develop methodology that may have important practical implications for early identification of children at risk for developing attention deficit disorder.